1. Field of the Invention
The present invention relates to a digital image processing device, more particularly to an image processing device of a digital camera.
2. Description of the Prior Art
At present, the storage method for photographs of digital cameras uses the JPEG compressing technique to compress the photograph and then store the compressed data. However, this method cannot process the compressed data flexibly, therefore cannot maximize the use of memory devices.
The conventional JPEG compressing technique uses Discrete Cosine Transform (DCT) coding method. In this method, imagine an image is a brick wall constructed by the DCT coefficients, the brick is constructed by individual DCT block. Compressing data can be seen as knocking the end portion of the brick and exposing the indentations and compressing the bricks with indentations. The compressed brick wall leaves filling slits and obscures the image (see FIG. 1). Furthermore, if part of the image data is eliminated to store the rest of the image data in the limited space, then part of the image may be lost. For example, an image which was originally a person's figure may lose its upper half, leaving the lower half intact.
FIG. 2 shows the conventional digital camera, including: a lens 1, a JPEG compressing device 2, a memory device 3, a decompressing device 4, and an image display device 5. Lens 1 is used to take in a digital image. JPEG compressing device 2 is used to compress the input digital image. The memory device 3 is used to store the compressed digital image. The decompressing device 4 is used to decompress the compressed digital image stored in the memory device 3. The image display device 5 (for example, liquid crystal display or computer) is used to display the decompressed image data file. Here, the image stored in the memory device 3 cannot be trimmed and thus the use of the memory device 3 cannot be maximized.